On 13 April 2013 13:26, Saptarshi Purkayastha <sun...@gmail.com> wrote:
> I think we should be Calendar agnostic in code and like most i18n capable > systems, not expect the timestamp in the database to be Calendar-specific > Postgres for instance uses Julian calendar internally. But still supports > many different systems, much more than standard SQL asks for. > Java similar uses long values, instead of Calendar-specific > representations. > > My point is, Java, Postgres (and MySQL) are well designed to work by being > calendar-agnostic. > Also, > Joda-time<http://joda-time.sourceforge.net/apidocs/org/joda/time/chrono/package-summary.html>provides > nice Chronology classes for different calendars, which we can use > for localized storing, retrieving or converting > Am I right in thinking joda-time is now integrated into the java.time package of java 8? > > For the JavaME app in one of the releases, we did have a custom calendar > component. > Having it display BS, Ethiopian or anything else, should be fairly easy. > But yes, very few low-end Java phones are locale specific. > > > --- > Regards, > Saptarshi PURKAYASTHA > > My Tech Blog: http://sunnytalkstech.blogspot.com > You Live by CHOICE, Not by CHANCE > > > On 13 April 2013 10:36, Jason Pickering <jason.p.picker...@gmail.com>wrote: > >> Hi Saptarshi, >> Yes, I cannot speculate really why DHIS2 only supports the Gregorian >> calendar, but this issue I think has been discussed a few times on the list >> before (perhaps for other countries). >> >> I feel the best approach would be to store all of the data with Gregorian >> dates, but what is shown through the web UI would be the calendar system of >> the particular instance. I am not even sure if databases like Postgres and >> MySQL (much less the operating system itself) would support non Gregorian >> calendar systems. >> >> As for data exchange, I see no immediate need for this, but if data is >> stored in Gregorian format ( I suppose the de facto international >> standard), then perhaps data exchange would be somewhat easier, but this is >> just speculation of course. >> >> Thanks for the link to the BS date picker. Does not seem to difficult to >> solve at least this problem.The bigger issue as I see it would be data >> entry through mobiles. At least the J2ME app uses the system calendar, and >> do not think that non-Gregorian systems are even supported on any phone? >> >> Best regards, >> Jason >> >> >> >> >> >> On Fri, Apr 12, 2013 at 5:16 PM, Saptarshi Purkayastha >> <sun...@gmail.com>wrote: >> >>> Hi Jason, >>> >>> When you say the system currently only support Gregorian calendar, I >>> wonder if that's a fact of JavaScript widgets >>> But while I was writing this email, a quick search in the code base >>> shows that we've instantiated Gregorian calendar at many places instead of >>> using the more localized Calendar.getInstance(). The first task would be >>> move to using this >>> >>> Secondly, is conversion between Gregorian dates and some other calendar >>> really required. If data is exchanged between different systems with >>> different calendars, this is important. But if we are storing a timestamp >>> in database, it should be fine to store it in the locale calendar. So I am >>> not too keen, unless really required to use the maps that allow co-relating >>> dates between calendar systems. >>> >>> Thirdly, there are quite a few (and fairly easy to write new JavaScript >>> calendars) to suite different locales. The care that we need to take is >>> being able to retrieve the correct calendar based on the set locale. A >>> simple BS calendar JS - >>> http://sajanmaharjan.com.np/my-works/nepali-datepicker-ui/ >>> >>> --- >>> Regards, >>> Saptarshi PURKAYASTHA >>> >>> My Tech Blog: http://sunnytalkstech.blogspot.com >>> You Live by CHOICE, Not by CHANCE >>> >>> >>> On 12 April 2013 12:56, Jason Pickering <jason.p.picker...@gmail.com>wrote: >>> >>>> Hi Devs, >>>> I have a question regarding non-Gregorian (Western) calendar systems. >>>> This issue has come up in a couple of different places which I know of, >>>> namely Ethiopia (Ethiopian calendar) and Afghanistan (Solar Hijri >>>> calendar). Currently, the system only supports a Gregorian calendar system, >>>> but I am trying to think of ways how we can support different >>>> ones, specifically the Bikram Sambat (BS) calendar system used in Nepal. >>>> >>>> >>>> There appears to be no easy way to convert between a Gregorian >>>> calendar. I dug out some code here >>>> <https://github.com/bahadurbaniya/Date-Converter-Bikram-Sambat-to-English-Date> >>>> which >>>> will convert between Gregorian dates and BS dates (but not the other way >>>> around). The approach is to use a look-up table, because of the fact that >>>> it seems to be difficult (if not impossible) to calculate the >>>> conversion algorithmically. >>>> >>>> This leads me to my question. Would it be possible that we consider >>>> adding a "Calendar system" to the application. The default would be >>>> "Gregorian", which is currently the case. The Second alternative might be >>>> "Bikram Sambat". This would require someone to prepopulate the system with >>>> periods (BS months, quarters and years) which would be calculated through >>>> some other means (common Lisp code >>>> here<http://emr.cs.uiuc.edu/~reingold/calendar.l> which >>>> may be able to do this). These would be in Gregorian periods, but instead >>>> of the system calculating future periods, they would have to be >>>> pre-calculated and entered/imported into the system somehow. >>>> >>>> The second part of this (which I think may be more difficult) is the >>>> use of the JavaScript Gregorian calendar throughout the system. For data >>>> entry of aggregate data, it would not to be too problematic. But for the >>>> tracker module (and other places in the system), a Gregorian Javascript >>>> widget is used, and it would seem to be potentially difficult to replace >>>> this. >>>> >>>> Could the developers comment on feasibility and possible level of >>>> effort? >>>> >>>> Best regards, >>>> Jason >>>> >>>> >>>> _______________________________________________ >>>> Mailing list: https://launchpad.net/~dhis2-devs >>>> Post to : dhis2-devs@lists.launchpad.net >>>> Unsubscribe : https://launchpad.net/~dhis2-devs >>>> More help : https://help.launchpad.net/ListHelp >>>> >>>> >>> >> > > _______________________________________________ > Mailing list: https://launchpad.net/~dhis2-devs > Post to : dhis2-devs@lists.launchpad.net > Unsubscribe : https://launchpad.net/~dhis2-devs > More help : https://help.launchpad.net/ListHelp > >
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